Veteran White House correspondent Helen Thomas smiles as she leaves the White House after attending a briefing in October 2007.

WASHINGTON — Helen Thomas, whose keen curiosity, unquenchable drive and celebrated constancy made her a trailblazing White House correspondent in a press corps dominated by men and later the dean of the White House briefing room, died Saturday at home in Washington. She was 92.

Her death was announced by the Gridiron Club , one of Washington’s leading news societies. Thomas was a past president of that organization.

Thomas covered every president from John F. Kennedy to Barack Obama for United Press International and, later, Hearst Newspapers. To her colleagues, she was the unofficial but undisputed head of the press corps — her status ratified by her signature line at the end of every White House news conference, “Thank you, Mr. President.”

Her blunt questions and sharp tone made her a familiar personality not only in the parochial world inside the Washington Beltway but also among television audiences across the country.

“Helen was a true pioneer, opening doors and breaking down barriers for generations of women in journalism,” Obama said in a statement Saturday. “She never failed to keep presidents — myself included — on their toes.”

Presidents grew to respect, even to like, Thomas for her forthrightness and energy, which sustained her well after the age at which most people have settled into retirement. President Bill Clinton gave her a cake on Aug. 4, 1997, her 77th birthday. Twelve years later, Obama gave her cupcakes for her 89th. At his first news conference in February 2009, Obama called on her, saying: “Helen, I’m excited. This is my inaugural moment.”

But 16 months later, Thomas abruptly announced her retirement from Hearst amid an uproar over her assertion that Jews should “get the hell out of Palestine” and go back where they belonged, perhaps to Germany and Poland. Her remarks, made almost offhandedly days earlier at a White House event, set off a storm when a videotape was posted.

In her retirement announcement, Thomas, whose parents immigrated to the United States from what is now Lebanon, said that she deeply regretted her remarks and that they did not reflect her “heartfelt belief” that peace would come to the Middle East only when all parties embraced “mutual respect and tolerance.”

“May that day come soon,” she said.

Thomas’ career bridged two eras, beginning during World War II when people got their news mostly from radio, newspapers and movie newsreels, and extending into the era of 24-hour information on cable television and the Internet. She resigned from UPI on May 16, 2000, a day after it was taken over by an organization with links to the Unification Church.

Weeks later, Thomas was hired by Hearst to write a twice-weekly column on national issues. She spent the last 10 years of her working life there.

When Thomas took a job as a radio writer for United Press in 1943 (15 years before it merged with the International News Service to become UPI), most female journalists wrote about social events and homemaking. The ones who covered war, crime and politics and congratulated one another over drinks at the press club were typically men.

She worked her way into full-time reporting and by the mid-1950s was covering federal agencies. She covered Kennedy’s presidential campaign in 1960, and when he won she became the first woman assigned to the White House full time by a news service.

Thomas was also the first woman to be elected an officer of the White House Correspondents’ Association and the first to serve as its president. In 1975, she became the first woman elected to the Gridiron Club, which for 90 years had been a men-only bastion of Washington journalists.

Thomas was known for her dawn-to-dark work hours, and she won her share of exclusives and near-exclusives. She was the only female print journalist to accompany President Richard M. Nixon on his breakthrough trip to China in 1972.

“Helen was a better reporter than she was a writer — but in her prime had more than her share of scoops the rest of us would try to match,” Mark Knoller, the longtime CBS News White House reporter, wrote in a Twitter message Saturday morning.

In the Watergate era, she was a favorite late-night confidante of Martha Mitchell, the wife of John N. Mitchell, Nixon’s attorney general and campaign official.

Martha Mitchell told Thomas that responsibility for the “third-rate burglary” at the Democratic headquarters in the Watergate complex in Washington and the cover-up that followed it had gone far above the midlevel officials who were implicated early on.

People with a vested interest in discrediting Martha Mitchell hinted that she was emotionally unstable and that she drank too much. But volatile or not, she was right. Thomas called Martha Mitchell, who died in 1976, “one of the first victims, and perhaps the only heroine, of the Watergate tidal wave.”

On April 22, 1981, three weeks and two days after the attempt on President Ronald Reagan’s life, Thomas and a reporter for The Associated Press interviewed the president, who told them of the “paralyzing pain” he had felt when a bullet went into his chest and of the panic that had overcome him when he could not breathe.

In 1971, Thomas married Douglas Cornell, a widower, who was about to retire as a White House reporter for The AP and was 14 years her senior. He died in 1982.

Thomas wrote half a dozen books. Her first, “Dateline: White House,” was published by Macmillan in 1975. Four others were published by Scribner: “Front Row at the White House: My Life and Times,” in 2000; “Thanks for the Memories, Mr. President: Wit and Wisdom From the Front Row at the White House,” in 2003; “Watchdogs of Democracy? The Waning Washington Press Corps and How It Has Failed the Public,” in 2006; and “Listen Up, Mr. President: Everything You Always Wanted Your President to Know and Do,” written with Craig Crawford, in 2009. With the illustrator Chip Bok, she also wrote a children’s book, “The Great White House Breakout,” about a little boy whose mother is president.

Helen Thomas was born in Winchester, Ky., on Aug. 4, 1920, one of 10 children of George and Mary Thomas. Her father, who could not read or write, encouraged his sons and daughters to go to college.

In 1942, when Thomas graduated from what is now Wayne State University in Detroit as an English major, the country was at war. She went to Washington to look for a job.

She found one, as a waitress. But she did not last long. “I didn’t smile enough,” she recalled years later.

The Washington Daily News soon hired her for a clerical post, and soon after that she began her career with the United Press news service.

“‘Where’d this girl come from?’ ” she asked rhetorically in an appearance before a women’s group in 1999. “I love my work, and I think that I was so lucky to pick a profession where it’s a joy to go to work every day.”

Before she left UPI in May 2000, the news service had been shrinking its payroll and closing bureaus for years, a decline that led to its takeover by News World Communications, the organization founded by the Rev. Sun Myung Moon, leader of the Unification Church. It also publishes The Washington Times, a favorite of conservative readers in Washington.

“I do not intend to stay,” she said on departing. “United Press International is a great news agency. It has made a remarkable mark in the annals of American journalism and has left a superb legacy for future journalists. I wish the new owners all the best, great stories and happy landings.”

Thomas bitterly opposed the war in Iraq and made no effort to appear neutral at White House news conferences, where some of her questions bordered on the prosecutorial. In “Watchdogs of Democracy?,” she wrote that most White House and Pentagon reporters had been too willing to accept the Bush administration’s rationale for going to war.

In an interview with The New York Times in May 2006, Thomas was typically uncompromising and unapologetic.

“How would you define the difference between a probing question and a rude one?” she was asked.